Question

我正在处理我的项目，这是一个烹饪助手，指示用户执行存储在二进制文件中的任务。我无法将输入保存到文件中并再次读回。我在下面提供了我的代码。建议我在我的代码中执行此操作或更正的方法。我想得到存储在二维数组中的指令......我必须得到输入，直到特定配方的说明和成分结束。我正在研究c ++

#include<iostream.h>
#include<conio.h>
#include<fstream.h>
#include<process.h>

class recipe {
    int laststate, icount, qcount;
    char recno;
    char name[50];
    float quantity[][50];
    char ingredient[][50];
    char instructions[][50];
    char unit[5];

public:

    recipe() {
        //if(laststate>recno)
        //recno=laststate;
        //else
        recno = 0;
    }


    void add() {
        char ch;
        cout << "\nEnter Recipe Name :";
        cin >> name;
        do {
            qcount = 0;
            cout << "\nQuantity, Unit and Ingredient Name :";
            cin >> quantity[qcount] >> unit[qcount] >> ingredient[qcount];
            qcount++;
            cout << "\nDo You Want to Enter More Ingredients :";
            cin >> ch;
        } while (ch == 'y' || ch == 'Y');
        do {
            icount = 0;
            cout << "\nEnter Instructions:\n";
            cin >> instructions[icount];
            icount++;
            cout << "\nDo You Want to Enter More Instructions :";
            cin >> ch;
        } while (ch == 'y' || ch == 'Y');
        recno++;
        laststate = recno;
    }

    void display() {
        cout << "Recipe Name :" << name << endl;
        cout << "Ingredients :" << endl;
        for (int i = 0; i <= qcount; i++)
            cout << i + 1 << "." << quantity[i] << " " << unit[i] << " ";//<<ingredient[i]<<endl;
        for (i = 0; i <= icount; i++)
            cout << i + 1 << "." << instructions[i] << endl;
        cout << "last state :" << laststate;
    }
};

void main() {
    clrscr();
    recipe R;
    char ch;
    fstream file("DATA.DAT", ios::binary | ios::app);
    do {
        R.add();
        file.write((char*)&R, sizeof(R));
        cout << "DYWTC :";
        cin >> ch;
    } while (ch == 'y' || ch == 'Y');

    while (!file.eof()) {
        file.read((char*)&R, sizeof(R));
        R.display();
    }
    file.close();
    getch();
}

Answer 1

在一系列写入之后，您在文件的最后有一个文件位置。当你开始阅读时，你仍然在文件的末尾，没有什么可读的。

要回到起点，您可以进行搜寻/** * Create an unset function using Lodash * @param state * @param payload */ unsetById: ( state, payload ) => { // Remove the item Vue.delete( state.data, _.findIndex( state.data,{ id: payload.id } ) ); // Emit an event to the event bus EventBus.$emit( 'screen-deleted' ); }。

此外，要同时启用阅读和写作，您可能还需要在file.seekg(0, ios::beg);的调用中添加ios::in | ios::out。

从二进制文件c ++中读取字符串数组

1 个答案: